Collagen composition of hypertrophic scar connective tissue matrix shows differences in proportions of collagen types. In addition, type I collagen has an altered hydroxyproline to proline ratio as compared to normal human type I dermise collagen. Biochemical structural studies of hypertrophic scar collagen are proposed. Compared to normal human dermis, hypertrophic scar is richer in types V, III and type I trimer collagnes. More detailed structural studies of reducible covalent cross links and sugar make up of these collagen typs, compared to normal skin extracted collagens, will be studied. Hydroxylysinonorleucine and dihydroxylysinonorleucine, lysine and hyroxylysine derived reducible cross links between collagen alpha chains will be isolated and quantified. Galactosyl hydroxylysine and glucosylgalactosyl hydroxylysine contents of collagens isolated from hypertrophic scars will be compared to normal dermis. Loci of hydroxyproline deficiency in hypertrophic scar type I collagen alpha chain will be identified by amino acid analysis of purified cyanogen bromide derived peptides. Collagen synthesis and collagenase activity will be studied in organ cultures of hypertrophic scar explants. Hydroxyproline content of newly synthesized type I collagen alpha chains will be measured. Increasing hydroxyproline content of explants type I collagen will be investigated by the addition of known Prolyl Hydroxylase cofactors such as ascorbate, yield Ketoglutarate, iron and lactate. Hypertrophic scar explants required epidermal cell layer for production of mammalian collagenase. Hydrocortisone and insulin supplements inhibit collagenase production. Characterization of collagenase and control of its secretion and synthesis will be studied in organ culture.